Astronomer Galileo Galilei played a major role in the Scientific Revolution. Using an improved telescope, Galileo discovered the moons of the planet Jupiter and the phases of the planet Venus. For a long time, people believed Earth to be the center of the solar system. Galilei, however, proved that Earth, like other planets, revolves around the Sun. He was the first to observe lunar mountains, sunspots, and Saturn's rings. Choose the best summary of the above passage. A. Galileo spent years trying to form a theory on planetary movements and positions. B. Galileo was an astronomer who discovered important facts about the solar system. C. Galileo enjoyed solving mathematical equations and making scientific discoveries. D. Galileo proved to people that the Earth, like other planets, revolves around the Sun.